package com.niuxiaofa.newlaw.View;

import android.content.Context;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.animation.TranslateAnimation;
import android.widget.ScrollView;

/**
 * @ClassName MyScrollView
 * @Description TODO
 * @Author Gxjkz
 * @Date 2020/8/26 15:44
 * @Version 1.0
 */
public class MyScrollView extends ScrollView {

    // 拖动的距离 size = 4 的意思 仅仅同意拖动屏幕的1/4
    private static final int size = 4;
    private View inner;
    private float y;
    private Rect normal = new Rect();


    public OnScrollListener listener;


    public void setOnscroll(OnScrollListener onscroll) {
        this.listener = onscroll;
    }

    public Callbacks mCallbacks;

    public void setCallbacks(Callbacks callbacks) {
        this.mCallbacks = callbacks;
    }

    //重写原生onScrollChanged方法，将参数传递给接口，由接口传递出去
    @Override
    protected void onScrollChanged(int l, int t, int oldl, int oldt) {
        super.onScrollChanged(l, t, oldl, oldt);

        if (listener != null) {

            //这里我只传了垂直滑动的距离
            listener.onScroll(t);


        }
        if (mCallbacks!=null){
            mCallbacks.onScrollChanged(l, t, oldl, oldt);
        }
    }
    //设置接口
    public interface OnScrollListener {
        void onScroll(float scrollY);

    }

    public MyScrollView(Context context) {
        super(context);
    }

    public MyScrollView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();
        if (getChildCount() > 0) {
            inner = getChildAt(0);
        }
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        if (inner == null) {
            return super.onTouchEvent(ev);
        } else {
            commOnTouchEvent(ev);
        }
        return super.onTouchEvent(ev);
    }


    //定义接口用于回调
    public interface Callbacks {
        void onScrollChanged(int x, int y, int oldx, int oldy);
    }


    public void commOnTouchEvent(MotionEvent ev) {
        int action = ev.getAction();
        switch (action) {
            case MotionEvent.ACTION_DOWN:
                y = ev.getY();
                break;
            case MotionEvent.ACTION_UP:
                if (isNeedAnimation()) {
                    // Log.v("mlguitar", "will up and animation");
                    animation();
                }
                break;
            case MotionEvent.ACTION_MOVE:
                final float preY = y;
                float nowY = ev.getY();
                /**
                 * size=4 表示 拖动的距离为屏幕的高度的1/4
                 */
                int deltaY = (int) (preY - nowY) / size;
                // 滚动
                // scrollBy(0, deltaY);

                y = nowY;


                // 当滚动到最上或者最下时就不会再滚动。这时移动布局
                if (isNeedMove()) {
                    if (normal.isEmpty()) {
                        // 保存正常的布局位置
                        normal.set(inner.getLeft(), inner.getTop(),
                                inner.getRight(), inner.getBottom());
                        return;
                    }
                    int yy = inner.getTop() - deltaY;

                    // 移动布局
                    inner.layout(inner.getLeft(), yy, inner.getRight(),
                            inner.getBottom() - deltaY);

                }

                break;
            default:
                break;
        }
    }

    public void setLinnerHight(int yy) {
//        int yy = inner.getTop() - deltaY;
//        inner.layout(inner.getLeft(), yy, inner.getRight(),
//                inner.getBottom() - deltaY);
//        inner.setTranslationY(deltaY);
//        inner.layout(inner.getLeft(), yy, inner.getRight(),
//                1920);
        this.smoothScrollTo(0, yy);
    }


    // 开启动画移动
    public void animation() {
        // 开启移动动画
        TranslateAnimation ta = new TranslateAnimation(0, 0, inner.getTop(),
                normal.top);
        ta.setDuration(200);
        inner.startAnimation(ta);
        // 设置回到正常的布局位置
        inner.layout(normal.left, normal.top, normal.right, normal.bottom);
        normal.setEmpty();
    }

    // 是否须要开启动画
    public boolean isNeedAnimation() {
        return !normal.isEmpty();
    }

    // 是否须要移动布局
    public boolean isNeedMove() {
        int offset = inner.getMeasuredHeight() - getHeight();
        int scrollY = getScrollY();
        if (scrollY == 0 || scrollY == offset) {
            return true;
        }
        return false;
    }




}
